Various devices to dilute or otherwise protect against smoke have over the years been proposed and are documented in the patent literature. However, it appears the inventors were not cognizant of the venturi effect which tends to entrain surrounding gas and thereby rendering the various proposed inventions non functioning or very inefficient for their intended purpose. This is also evidenced in the current technology in use particularly in aircraft cockpit for smoke evacuation purposes where dilution by outside air is the means of attempting to cope with dense continuous smoke in the cockpit window in severe circumstances. Neither of these procedures work to eliminate a continuous dense smoke problem in the cockpit. Opening the window has little or no effect because of the aerodynamics surrounding the fuselage where the windows are located and the small controllable air nozzles merely entrain the surrounding smoke and mix it with the airstream thereby having little or no effect during emergencies where the smoke cannot be stopped.
The present invention overcomes these fundamental deficiencies and in addition provides added advantages as disclosed below.
It is noteworthy to observe that the problem of dense vision impairing smoke is particularity acute in aircraft and there is a long history of smoke accidents where pilots have been unable to see to safely control and land the aircraft. Likewise, although the historical record may not be as catastrophic as in the aviation industry, a similar problem exists on submarines where operators need to be able to see to turn off reactors and otherwise manipulate controls read instruments to control a fire/smoke emergency. U.S. Pat. No. 4,832,287 issued to Werjefelt addresses this safety dilemma and does provide vision for pilots and other operators regardless of smoke density. However, depending on what criteria may be applied, the present invention may prove to be a substantial improvement in that it solves the problem in a quite different way with less cumbersome paraphernalia for the users to contend with. While it may not provide as guaranteed a protection of vision as that described in the Werjefelt patent, it may in certain applications provide a very satisfactory level of safety for the purpose of pilot or other operator vision assurance.